JPH0137844Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a chuck for gripping a rotary cutting tool such as a drill, and particularly a holding tube into which a rotary cutting tool or an adapter for holding the same is inserted; This invention relates to a roll lock type chuck in which a plurality of needle rollers are interposed between a tightening tube rotatably mounted on the outer circumferential surface of the chuck.

"Prior Art" Conventionally, as a chuck for gripping a rotary cutting tool, there is a holding cylinder into which the target tool is directly or indirectly inserted, and a chuck that is rotatably attached to the outer peripheral surface of the holding cylinder at a predetermined distance. A large number of needle rollers are arranged in multiple stages over the entire surface with axes that make an appropriate inclination angle with respect to these axes between the circumferential surface between the tightening tube and the tightening tube. A roll-lock type chuck in which the holding cylinder contracts and restores itself while the roller rotates and revolves around its axis is already known (Utility Model Publication No. 41-23987). As shown in the figure, a roller cage 60 having a number of holding holes 61 corresponding to the needle rollers 30 is inserted between the circumferential surfaces of both the cylindrical bodies, and the needle rollers 30 are
... is rotatably held in a predetermined position. However, with this configuration, the same number of holding holes 61 as the needle rollers 30 ... must be formed, which makes machining troublesome and increases costs. Since the frame portion 62 between the holding holes 61 requires a certain width for strength, a certain width is required for the number of needle rollers 30..., and as a result, the rollers 30...
Due to the limited number of attachments, the tightening force acting in the direction of contraction of the holding cylinder was also relatively small.

In order to eliminate this drawback, for example, as shown in FIG. 5, a roller cage 70 inserted between the holding tube and the tightening tube is provided with an appropriate spacing over almost the entire circumferential surface between the cylinders. A plurality of needle rollers 3 are arranged in the circumferential direction in the formed holding hole 71.
By loosely fitting and retaining the rollers 30..., it is possible to increase the number of rollers 30... that can be installed on the same circumference, and as a result, the tightening force acting in the direction of contraction of the holding cylinder can be significantly increased. A technology has been proposed that can do this. (Utility Model Publication No. 55-20405) "Problems to be Solved by the Invention" However, in this conventional technology, when the tightening cylinder is rotated in the direction of contraction of the holding cylinder and the cutting tool is tightened, the inside of each holding hole is Since the plurality of needle rollers 30 held in the roller rotate in the same direction, the rollers 30 are biased in one direction and come into contact with each other during rotation, preventing smooth rotation of the rollers 30. , friction torque is generated between the tightening cylinder or the holding cylinder in contact with the rollers 30..., and as a result, the transmission efficiency decreases due to an increase in the friction torque, and the number of the rollers 30... increases. This has the disadvantage that the tightening force does not increase relatively, and therefore the operating force increases accordingly, leading to a decrease in operability.

The present invention solves this problem by preventing the occurrence of sliding friction caused by the collision of adjacent rollers, and by allowing smooth rotation at a predetermined position, the rotational operating force of the tightening cylinder is maintained. It is an object of the present invention to provide a chuck that can effectively act on a cylinder and operate the tightening cylinder with extremely light force.

Another object of the present invention is to provide a chuck that can significantly increase the tightening force acting in the direction of contraction of the holding cylinder compared to the prior art.

``Means for Solving the Problems'' The structure of the chuck according to the present invention to achieve the object of the above invention is such that the outer circumferential surface is formed in a tapered shape, and the chuck has a structure in which the target tool is directly or indirectly inserted into the chuck. A cylinder 11, a tightening cylinder 20 rotatably attached to the outer peripheral surface of the holding cylinder 11 at a predetermined interval, and both cylinders 1.
The needle roller 30 is inserted between the 1 and 20 peripheral surfaces.
A roller cage 40 is provided with a plurality of holding holes 41 formed over almost the entire circumferential surface for holding . is rotatably held, and by rotating the tightening tube 20, the needle rollers 30... are rotated and spirally revolved, and the holding tube 11 is contracted and restored. holding hole 41
A plurality of needle rollers 30 held within...
A roller holding means 50 is provided to rotatably hold the rollers while maintaining a predetermined distance between them.

In this case, the roller holding means includes needle rollers 30 at both ends of the holding hole 41 of the roller cage 40.
. . . A support portion may be formed to rotatably support both ends, or a spacer or the like may be used to rotatably support the needle roller 30 . It may be configured to be fitted and fixed into the holding hole 41.

Further, if the end portions of the needle rollers 30 are cylindrical, the shape of the holding means 50 is adjusted to the tip radius.
If the needle roller 30 has a concave shape and is rotatably supported at two points (see examples below), and if the end of the needle roller 30 is hemispherical,
The positions on the axis of the end faces of the needle rollers 30 may be recessed in an R shape, the shape of the holding means 50 may be formed into a pivot shape, and the holding means 50 may be rotatably supported at one point.

And such roller cages and spacers are
For example, there is a method in which the holding hole 41 is formed by punching a thin plate and then formed into a predetermined conical shape, or a method in which the holding hole 41 is formed by lost wax casting, which can be provided relatively easily and at low cost.

Further, the number of needle rollers 30 loaded into the holding hole 41 can be two, three, or more, and the number can be varied depending on the purpose of use.

"Operation" According to this technical means, a plurality of needle rollers 30 are loaded into the holding hole 41, and the adjacent rollers 30 are rotatably supported with a small interval maintained between them. Therefore, even when the tightening cylinder 20 is rotated in the direction of contraction of the holding cylinder 11 to tighten the cutting tool, the plurality of needle rollers 30 held in each holding hole 41 are still rotating. It rotates in a predetermined position without being biased in one direction.

Therefore, the rotating operation force of the tightening cylinder is transferred to the holding cylinder 11 without causing sliding friction between the rollers 30...
The clamping cylinder can be operated with an extremely light force, and as a result, the clamping force acting in the direction of contraction of the holding cylinder 11 can be significantly increased compared to the conventional technology. .

Further, in a preferred embodiment of the present invention, by forming the roller holding means 50 on both ends of the holding holes 41 of the roller cage 40, it is possible to hold a plurality of needle rollers 30 at minute intervals,
As a result, the area of the holding holes 41 can be reduced, and a large number of holding holes 41 can be formed on the peripheral surface of the roller cage.
This allows for higher operability and improved tightening force.

Embodiments Hereinafter, preferred embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, unless otherwise specifically stated, the dimensions, materials, shapes, and relative positions of the components described in this example are not intended to limit the scope of this invention, but are merely illustrative. Just an example.

1 to 3 show an embodiment of the chuck according to the present invention, FIG. 1 is a longitudinal sectional front view, FIG. 2 is a plan view of the main part showing the shape of the roller cage, and FIG. 3 is a
FIG. 2 is an enlarged view of FIG. 2;

10 is a holder body attached to the main shaft 2;
Shank 15 and holding cylinder 1 via flange 14
1 is integrally formed along the axis C-C'.

The holding cylinder 11 has a cylindrical inner circumferential surface 11b into which the cutting tool 1 as a target tool is inserted directly or an adapter for holding the cutting tool 1, and an outer circumferential surface formed in a tapered shape from the base end. 11a, and around the outer circumferential surface 11a, a tightening tube 20 whose inner circumferential surface 20a is formed into a tapered surface similar to the outer circumferential surface 11a of the holding cylinder is rotatably mounted at a predetermined interval. has been done.

Then, the tightening cylinder inner circumferential surface 20a and the holding cylinder 11
A plurality of holding holes 41 that are inserted between the circumferential surfaces of both the cylindrical bodies 11 and 20 and that hold the needle rollers 30 are formed on almost the entire circumferential surface within the circumferential gap formed between the outer circumferential surface 11a and the outer circumferential surface 11a. The roller cage 40 previously formed is inserted, and the roller cage 40 is secured by retaining rings 13 and 22 attached to both ends of the retaining tube 11 and the tightening tube 20 on the peripheral surfaces 11a and 20a. The axial movement of 40 is restricted.

As shown in FIG. 2, the roller cage 40 has a large number of holding holes arranged in parallel in multiple stages in the axial direction. It has 41.

The holding hole 41 is connected to the tightening cylinder 20 and the holding cylinder 1.
1, each pair of R-shaped recesses 5 are parallel to the inclination angle α on both sides parallel to the circumferential direction.
0... are formed in a number corresponding to the number of needle rollers 30..., and protrusions 51 are formed between adjacent R-shaped recesses 50, and cylindrical needle rollers 30... are formed in the R-shaped recesses 50. Load.

As a result, the arrangement direction of the needle rollers 30 is maintained parallel to the axis C-C' of the tightening cylinder 20 and the holding cylinder 11 along the direction of the inclination angle α, and both ends thereof The portion is the R-shaped recessed portion 50.
It is rotatably held in point contact on the circumferential line of ..., and furthermore, the adjacent needle roller 30
... are regulated in position by the projections 51 of the R-shaped recesses 50, and are arranged so as to have a constant minute gap at all times.

According to this embodiment, by rotating the tightening cylinder 20, the needle rollers 30 rotate and revolve helically, and the holding cylinder 11 can be contracted and restored, and the respective holding cylinders 11 can be contracted and restored. hole 4
A plurality of needle rollers 30 held in 1...
...They are rotated while maintaining a predetermined distance between them without being biased to one side, and the above-mentioned effects are smoothly achieved.

"Effects of the Invention" As described above, according to the present invention, it is possible to prevent the occurrence of sliding friction caused by the contact between adjacent rollers and to rotate the tightening cylinder smoothly at a predetermined position. The dynamic operating force can be effectively applied to the holding tube, and the tightening tube can be operated with an extremely light force, and the tightening force acting in the direction of contraction of the holding tube can be significantly increased compared to the prior art. I can do it.
It has various effects such as

[Brief explanation of the drawing]

1 to 3 show an embodiment of the chuck according to the present invention, FIG. 1 is a longitudinal sectional front view, FIG. 2 is a plan view of the main part showing the shape of the roller cage, and FIG. 3 is a
FIG. 2 is an enlarged view of FIG. 2; FIG. 4 and FIG. 5 are both enlarged views of essential parts showing the shape of a roller cage according to the prior art. 11: Holding tube, 20: Tightening tube, 30...: Needle roller, 40: Roller cage, 41: Holding hole, 50...: Holding means.

Claims (1)

[Scope of utility model registration request] A holding cylinder into which a target tool is inserted directly or indirectly, a tightening cylinder which is rotatably attached to the outer circumferential surface of the holding cylinder at a predetermined distance, and a needle which is inserted between the circumferential surfaces of both cylinders. a roller cage in which a plurality of holding holes for holding rollers are formed over almost the entire circumferential surface, and a plurality of needle rollers arranged in parallel in the circumferential direction are rotatably held in each of the holding holes,
In the chuck, the needle roller is rotated on its own axis and spirally revolved to contract and restore the holding cylinder by rotating the tightening cylinder, and the plurality of chucks are rotatably held in the respective holding holes. A chuck characterized in that a roller holding means is provided for rotatably holding the needle rollers of the book while maintaining a predetermined distance between them.